Tag: fossils

Australian Megafauna A-Z: B is for Barawertornis

Posted on by Travis Park in Australian Megafauna A-Z, Australian palaeo, Dromornithids

Just over a month ago I started a new series here on Blogozoic, the Australian megafauna A-Z, in order to show people the weird and wonderful products of the evolutionary and geographic isolation of Australia. In the first post of the series I wrote about Alkwertatherium, a large marsupial that roamed the Northern Territory in the Late Miocene. Now we move onto the letter B and this time the animal, somewhat appropriately, is a bird.

The group to which this bird belongs is the Dromornithids. Those of you with very good memories may remember I wrote a post giving an introduction to these giant, extinct, flightless birds back in February (click here to read it). This time however I will focus on one species of dromornithid in particular, the species in question is Barawertornis tedfordi.

A reconstruction of Dromornis stirtoni by the fantastic palaeo-artist Peter Trusler.
A reconstruction of the dromornithid Dromornis stirtoni by the fantastic palaeo-artist Peter Trusler.

Barawertornis tedfordi isamong the oldest known dromornithids, dating to the Late Oligocene to Early Miocene. Its generic name means ‘ground bird’ and it specific name is in honour of the vertebrate palaentologist Richard Tedford, who was one of the first people to collect dromornithid remains in Australia. The holotype, a partial left femur, was described along with other partial hind limb fragments and a dorsal vertebra by Vickers-Rich (1979). Little more was discovered of the taxon until 2010, when Nguyen and colleagues described multiple partial femora, tibiotarsi and tarsometatarsi from the Riversleigh World Heritage Area in north-western Queensland. This new material allowed the researchers to better understand the relationship of B. tedfordi to other dromornithids as well as make some inferences about how this animal may have lived.

Some of the new material described in 2010 by Nguyen and colleagues. You can see the fragmentary nature of the material, one of the joys of palaeo in Australia! Image from Nguyen et al. 2010.
Some of the new material described in 2010 by Nguyen and colleagues. You can see the fragmentary nature of the material, one of the joys of palaeo in Australia! Image from Nguyen et al. 2010.

As well as being one of the oldest dromornithid species, B. tedfordi is also the smallest known species of dromornithid and would have been similar in size to the extant southern cassowary (Casuarius casuarius), with an estimated mass of around 45 – 65 kg (Nguyen et al. 2010). Furthermore, the relative proportions of the hind limb bones in are also most similar to that of the southern cassowary, suggesting that it may have been capable of similar cursorial (walking and running) abilities. With Australia being mainly covered by forest during the Early Miocene it makes sense that B. tedfordi would have converged upon a similar physique to the cassowary that today still roams the forests of north-eastern Australia and Papua New Guinea.

Anyone who thinks birds aren't related to dinosaurs need to look at the cassowary. Barawertornis is thought to have lived in a similar manner to this modern day forest-dweller. Image from www.flickr.com.
Anyone who thinks birds aren’t dinosaurs need to look at the cassowary. Barawertornis is thought to have lived in a similar manner to this modern day forest-dweller. Image from http://www.flickr.com.

The phylogenetic position of B. tedfordi is also still not certain. Previous analyses (e.g. Murray & Vickers-Rich 2004) and the strict consensus of the analysis by Nguyen et al. (2010) found that B. tedfordi was the sister taxon to all other dromornithids. However, Nguyen et al. (2010) also found weak support for B. tedfordi forming a clade with Ilbandornis sp., I. woodburnei, Dromornis planei, and D. stirtoni. The fragmentary nature of most dromornithid material however prevents more definitive statements being made about their phylogenetic relationships at present.

The phylogeny on the left shows the currently accepted position of B. tedfordi. The phylogeny on the right shows the position that Nguyen et al. 2010 found weak support for. Images modified from Nguyen et al. 2010.
The phylogeny on the left shows the currently accepted position of B. tedfordi. The phylogeny on the right shows the position that Nguyen et al. 2010 found weak support for. Images modified from Nguyen et al. 2010.

So that’s B done, I’ll leave it up to you clever people to figure out what letter is coming next. Stay tuned…

References

MURRAY, P.F. & VICKERS-RICH, P., 2004. Magnificent Mihirungs: the Colossal Flightless Birds of the Australian Dreamtime. Indiana University Press, Bloomington, 410 pp.

NGUYEN, J.M.T., BOLES, W.E. & HAND, S.J., 2010. New material of Barawertornis tedfordi, a dromornithid bird from the Oligo- Miocene of Australia, and its phylogenetic implications. Records of the Australian Museum 62, 45–60.

Other posts in the Australian Megafauna A-Z series:

A is for Alkwertatherium

Australian fossil penguins – the story so far…

Posted on by Travis Park in Australian palaeo, Penguins, Personal research

Everybody loves penguins. From Happy Feet to the plethora of nature documentaries on the breeding cycle of the Emperor penguin, who can resist that awkward shuffle on land and the effortless grace in water? One facet of the penguin story that most people won’t be as familiar with is penguin palaeontology. This field has seen a renaissance since the early 1990’s with New Zealand and South America and Antarctica leading the way and South Africa also having their fair share of attention. One region that has been left out of this flurry of penguin research is Australia.

The published fossil record of penguins in Australia, although limited compared to that of Antarctica, New Zealand and South America, spans some 40 million years from the late Eocene to Recent (Ksepka and Ando, 2011). The majority of previous work has been produced by one author, none other than George Gaylord Simpson (Simpson, 1957, 1959, 1965, 1970), with the first publication released in 1938 (Finlayson, 1938) and the last primary research conducted by Van Tets and O’Connor (1983) a 30 year lull! A total of ten different localities are known from South Australia and Victoria (Park and Fitzgerald, 2012). In addition to numerous unidentifiable fragments, a total of five species have been named from the Australian material: Pachydyptes simpsoni (Eocene); Anthropodyptes gilli (Miocene); Pseudaptenodytes macraei (Miocene); Pseudaptenodytes minor (Miocene) and Tasidyptes hunteri (Holocene). Only two of these (A. gilli and P. macraei) are at present considered taxonomically distinct and only one species (P. simpsoni) is known from associated remains. All other species are based on individual and/or partial specimens, with the majority of specimens being too fragmentary for identification below the family level.

Holotype of Pachydyptes simpsoni. Unfortunately this is the most complete fossil penguin yet found in Australia, perhaps a reason for the lack of research! From Park & Fitzgerald, 2012. Photo taken E. M. G. Fitzgerald.
Holotype of Pachydyptes simpsoni. Unfortunately this is the most complete fossil penguin yet found in Australia, perhaps a reason for the lack of research! From Park & Fitzgerald, 2012. Photo taken by E. M. G. Fitzgerald.

A new paper co-authored by myself and Dr. Erich Fitzgerald (senior curator of vertebrate palaeontology at Museum Victoria) reviews the fossil record of penguins in Australia. Whilst the record is undoubtedly fragmentary, material is known from every epoch since the Eocene and virtually every find up until now has been by chance. So the potential is there for new discoveries to be made, should actually someone go and specifically look for fossil penguins. Furthermore, material has continued to accumulate in museum collections over the past 30 years despite the lack of research, some of it worthy of further study (keep your eyes peeled later in the year for that). So consider this an unfinished story, the fossil penguins of Australia have a few more tales to tell.

Link to the paper: http://museumvictoria.com.au/pages/41623/momv-2012-vol-69-pp309-325.pdf

References

Finlayson, H. H. 1938. On the occurrence of a fossil penguin in Miocene beds in South Australia. Transactions of the Royal Society of South Australia 62:14–17.

Ksepka, D. T., and T. Ando. 2011. Penguins Past, Present, and Future: Trends in the Evolution of the Sphenisciformes; pp. 155–186 in G. Dyke, and G. Kaiser (eds.), Living Dinosaurs. The Evolutionary History of Modern Birds. Wiley-Blackwell, West Sussex.

Park, T., and E. M. G. Fitzgerald. 2012. A review of Australian fossil penguins (Aves: Sphenisciformes). Memoirs of Museum Victoria 69: 309–325

Simpson, G. G. 1957. Australian fossil penguins, with remarks on penguin evolution and distribution. Records of the South Australian Museum 13:51–70.

Simpson, G. G. 1959. A new fossil penguin from Australia. Proceedings of the Royal Society of Victoria 71:113–119.

Simpson, G. G. 1965. New record of a fossil penguin in Australia. Proceedings of the Royal Society of Victoria 79:91–93.

Simpson, G. G. 1970. Miocene penguins from Victoria, Australia, Chubut, Argentina. Memoirs of the National Museum, Victoria 31:17–24.

Van Tets, G. F., and S. O’Connor. 1983. The Hunter Island penguin, an extinct new genus and species from a Tasmanian midden. Records of the Queen Victoria Museum 81:1–13.